MyBatis学习总结

1.引入jar包到lib目录下：只需要mybatis的一个mybatis.jar及数据库的jar包。

2。在src下新建xml配置文件，即上图中的conf.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>

    <!-- 定义别名 -->
    <typeAliases>
        <typeAlias type="com.hanqi.News" alias="News"/>
    
    </typeAliases>
    
    <!-- 环境配置 -->
        <environments default="test">
        <!-- 开发环境 -->
        <environment id="development">
            <!-- 事务管理器 -->
            <transactionManager type="JDBC" />
            <!-- 数据源 POOLED池连接;NOPOOLED 非池连接-->
            <dataSource type="POOLED">
                <property name="driver" value="oracle.jdbc.driver.OracleDriver" />
                <property name="url" value="jdbc:oracle:thin:@localhost:1521:orcl" />
                <property name="username" value="test" />
                <property name="password" value="test" />
            </dataSource>
        </environment>
        <!-- 测试环境 -->
        <environment id="test">
            <transactionManager type="JDBC" />
            <dataSource type="POOLED">
                <property name="driver" value="oracle.jdbc.driver.OracleDriver" />
                <property name="url" value="jdbc:oracle:thin:@localhost:1521:orcl" />
                <property name="username" value="test" />
                <property name="password" value="test" />
            </dataSource>
        </environment>
    </environments>
    
    <mappers>
        <mapper resource="com/hanqi/newsMapper.xml"/>
        
        <mapper class="com.hanqi.newsInterface"/>
    </mappers>
</configuration>

3。新建数据库表NEWS，和实体类News.java

package com.hanqi;

import java.util.Date;

public class News {

    private Integer id;
    private String title;
    private String contant;
    private Date createdate;
    private String author;
    public News(Integer id, String title, String contant, String author) {
        super();
        this.id = id;
        this.title = title;
        this.contant = contant;
        this.author = author;
    }
    
    public News(String title, String contant, String author) {
        super();
        this.title = title;
        this.contant = contant;
        this.author = author;
    }


    public News(Integer id, String title) {
        super();
        this.id = id;
        this.title = title;
    }
    
    
    public News() {
    }


    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public String getTitle() {
        return title;
    }
    public void setTitle(String title) {
        this.title = title;
    }
    public String getContant() {
        return contant;
    }
    public void setContant(String contant) {
        this.contant = contant;
    }
    
    /**
     * @return the createdate
     */
    public Date getCreatedate() {
        return createdate;
    }
    /**
     * @param createdate the createdate to set
     */
    public void setCreatedate(Date createdate) {
        this.createdate = createdate;
    }
    /**
     * @return the author
     */
    public String getAuthor() {
        return author;
    }
    /**
     * @param author the author to set
     */
    public void setAuthor(String author) {
        this.author = author;
    }
    @Override
    public String toString() {
        return "News [id=" + id + ", title=" + title + ", contant=" + contant + ", createdate=" + createdate + "]";
    }
}

4.新建映射配置文件：newsMapper.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.hanqi.newsMapper">
    <!-- 
        根据id查询得到一个News对象
     -->
     <select id="getNewsByID" parameterType="int" resultType="News">
         select * from news where id=#{id}
     </select>
     <!-- 定义结果集 -->
     <resultMap type="News" id="newsList">
         <!--  <id property="id" column="news_id"/>
         <result property="title" column="tit"/>
     -->
     </resultMap>
     
         <!-- 多数据查询 -->
     <select id="getAllList" resultMap="newsList">
         select * from news
     
     </select>
     
     <!-- 定义条件集 -->
     <parameterMap type="java.util.HashMap" id="titlelike">
         <parameter property="tit"/>
         <parameter property="aut"/>
     
     </parameterMap>
     
     <!-- 传多个条件多数据查询 -->
     <select id="getList" parameterMap="titlelike" resultMap="newsList">
         select * from news where title like '%'||#{tit}||'%' and author like '%'||#{aut}||'%'
     
     </select>
     <insert id="insertNews" parameterType="News">
         insert into news (id, title, contant, createdate, author) values ( HIBERNATE_SEQUENCE.nextval, #{title}, #{contant}, sysdate, #{author})
     
     </insert>
</mapper>

5.新建测试用例，进行测试

package com.hanqi;

import static org.junit.Assert.*;

import java.io.IOException;
import java.io.Reader;
import java.util.*;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Test;

public class TestMyBatis {

    @Test
    public void test() throws Exception {
        //1.加载配置文件到输入流里
        Reader reader = Resources.getResourceAsReader("conf.xml");
        
        //2.创建工厂类SqlSessionFactory
        SqlSessionFactory ssf = new SqlSessionFactoryBuilder().build(reader);
        
        //3.获取sqlSession
        SqlSession ss = ssf.openSession();
        
        //4.调用数据库操作
        //单数据查询
        News n = ss.selectOne("com.hanqi.newsMapper.getNewsByID",77);
        
        //输出结果
        System.out.println("n=" + n);
        
        //插入数据
        News n1 = new News("ddd","eeee","aaa");
        
        int i = ss.insert("com.hanqi.newsMapper.insertNews", n1);
        
        System.out.println("insert="+ i);
        
        //查询数据
        List<News> ln = ss.selectList("com.hanqi.newsMapper.getAllList");
        
        System.out.println("ln=......"+ln);
        
        //条件查询
        HashMap<String, Object> hm = new HashMap<String, Object>();
        
        hm.put("tit", "d");
        hm.put("aut", "a");
        
        List<News> ln1 = ss.selectList("com.hanqi.newsMapper.getList",hm);
        
        System.out.println("ln1=#######"+ln1);
        
        //测试注解update
        News n2 = new News(95,"测试MyBatis","测试","测试");
        
        int i1 = ss.update("com.hanqi.newsInterface.updateNews", n2);
        
        System.out.println("n3="+i1);
        
        //注解查询
        List<News> ln2 = ss.selectList("com.hanqi.newsInterface.selectList");
        
        System.out.println("ln2=@@@@@@@@"+ln2);
        
        //提交
        ss.commit();
        //关闭session
        ss.close();
        //关闭流
        reader.close();
        
    }

}

6.也可以用注解代替映射配置文件，但是需要新建一个实体类对应的接口，在接口方法上加注解

package com.hanqi;

import java.util.List;

import org.apache.ibatis.annotations.*;

public interface newsInterface {
    
    @Update("update news set title=#{title}, contant=#{contant}, author=#{author} where id =#{id}")
    public int updateNews(News news);
    
    @Select("select * from news")
    public List<News> selectList();
}